A liquid crystal display (LCD) comprises an LCD panel, a backlight, a driving circuit board, a flexible circuit board, a source driver IC and a gate driver IC; the LCD panel mainly includes a lower polarizer, an array substrate, liquid crystals, a color filter (CF) substrate and an upper polarizer. The array substrate is provided with horizontal scanning signal lines, vertical data signal lines and thin-film transistor (TFT) switches, the TFT switches are configured to control the transmission of vertical data signals in accordance with horizontal scanning signals. The liquid crystals are interposed between the array substrate and the CF substrate. The orientation of the liquid crystals is controlled by applying voltages to the CF substrate and the array substrate. The CF substrate and the array substrate are sealed by a sealant. Anisotropic conductive adhesive is distributed in the sealant to achieve the conduction of the upper substrate and the lower substrate. As the LCD panel does not emit light, the backlight is required to provide light. The liquid crystals have different orientation angles under different voltages, and the intensity of light running through the liquid crystals is also different. The upper polarizer and the lower polarizer disposed on the outside of the LCD panel may control the polarization directions of light. Polarized light runs through corresponding CF to form monochromatic polarized light. An image pixel is displayed by the combination of three colors, namely red, green and blue. The horizontal scanning signals are configured to control the TFT switches. When the TFT switches are switched on, pixels may be charged. The vertical data signal lines control the orientation angles of the liquid crystals by transmitting signals to pixels. The array substrate is provided with an effective display area and an external lead area. The effective display area is a pixel area and is provided with pixel matrixes. The external lead area is respectively connected with the effective display area and the gate driver IC and the source driver IC and configured to transmit signals of the driving circuit board to the effective display area.
In the traditional LCD panel, two square signal repair lines are disposed along the circumference of the effective display area and configured to repair poor (defective) scanning lines or signal lines in the effective display area. However, if poor signal leads occurs in the external lead area, for instance, poor contact between the signal lead and the source driver IC or the gate driver IC, signal lead disconnection, etc., the leads cannot be repaired in this cases. Thus, if poor signal leads in the external lead area are detected after the cell-assembly process, only product rejection can be adopted for subsequent processing. Therefore, the waste of products can be caused, and hence the cost of products can be increased.
In summary, the traditional LCD panel cannot repair poor signal leads in the external lead area. Thus, the waste of products can be caused, and hence the cost of products can be increased.
In addition, other display panels, e.g., organic light-emitting diode (OLED) display panels, also have the problem of being difficult to repair poor signal leads.